Although answering to different lifestyles and located in different countries - one in an old residential quarter of Olivos near Buenos Aires, Argentina; the other a short-stay holiday home set into steep cliffs facing the Pacific Ocean at Cachagua, north of Valparaiso, Chile - the two homes designed by Mathias Klotz exude the same refined elegance. In both, an uncompromising orthogonal plan with clearly readable architectural volumes lends a formal rigueur, further underscored by interiors of rarefied elegance where the restrained use of just a few materials - concrete, steel, glass and wood - makes for quiet refinement.The holiday home built by Klotz in Chile - the B House - makes the very most of its spectacular setting on a cliff overlooking an ocean beach by making massive use of transparent glazed walls. Firmly anchored to the sloping terrain, the compact, rigorous geometry creates intermediate spaces between interior and exterior as well as secluded areas sheltered from the wind. The house is on two levels with a roof that becomes a terrace. The upper level is given over to the living area while the area below is a four-bedroom night zone. Klotz has predicated everything on a mix of flexibility and ambivalence. The living and dining area is a flexible space, a vast glazed area with nothing between it and the ocean except a loggia cantilevering out over the floor below with intermittent metal screens to shield it from the weather and glare. Hillside, the living area spills out beyond the huge stone fireplace onto a patio terrace sheltered by fair-face concrete walls. The lower level rests on a partly paved, partly grass terrace on a level with the swimming pool. Internal and exterior stairs link the two levels to provide a weave of communication pathways. For the L House in Argentina, Mathias Klotz teamed up with Edgardo Minond to create an essentially horizontal form where each environment relates directly to the exterior. The architectural programme is characterised by a sequential layout of environments and views connected by an internal corridor - a circulation route that really begins outside with the stepped path leading to the entrance next to an open carport under a pergola canopy adjoining the house. Inside, the main living area lies at right angles to the corridor. This large sitting-cum-dining room has an ample fireplace at one end. Contrasting wall textures afford a sensory materiality. The unrendered fair-face concrete wall closing off the southwest side forms a huge niche within which to hang paintings. Opposite, large full-height sliding glazed doors open out onto a terrace - protected by a concrete beam pergola - the swimming pool and lawn with outdoor sculptures. The strongly textured fair-face concrete wall separating the living area from the adjacent corridor seems to hover above the ground. Beyond, the corridor is a transparent glazed membrane giving full views onto the outside as it follows the sequenced environments - kitchen, square patio and large music room - and runs alongside an external paved walkway leading to the garden. The corridor ends before the night zone, a parallelepiped volume containing bedrooms on both ground and upper floors that stands as if apart from the rest of the house. The upper story of this, the only two-level volume, has a simple yet distinctive post and beam structure that runs like a concrete band around the whole perimeter. While secluded, the night zone enjoys the same intimate relationship with the exterior as the rest of the house. The upper level cantilevers over a transitional space leading into the garden; vertical concrete sun-shading slats protect the exposed west façade. The master bedroom on the upper level is a complex space with wooden partitions, a large fireplace, an extensive glazed façade overlooking the garden, and direct access to the roof that doubles as a terrace.